The invention disclosed herein relates to devices that assist in stabilizing door leaf or lamellae in a vertical running door against wind load applied to a side of the door.
Rollup doors comprising door leaf or lamella (hereinafter “lamella”) are typically supported at the left and right edges of the doorway to be covered by rigid door guides. The rigid door guides allow vertical movement of the lamella and support the left and right edge portions of the lamella against deflection perpendicular to the plane of the door or the plane of the lamella. The lamella are typically operatively connected between the left and right end portions to allow for rotation about an axis along the length of the lamella to allow for flexibility in the rollup direction. The operative connection between adjacent lamella is configured to resist separation between adjacent lamella if a lamella or lamellae is subjected to a perpendicular force. Adjacent connected lamella provide support against separation and deflection when the door is subject to a perpendicular load, such as a wind load.
Rollup doors comprised of lamellae are often used to provide a movable covering for an opening in a building or structure. When unrolled from a take-up drum to cover the opening, that is, when in the closed position, the bottom lamella typically rests against the bottom of the opening. Successive lamellae in the vertical direction abut the layer of lamellae directly below and above. The operative connection between adjacent lamellae maintain proper vertical alignment. Each lamella from the bottom of the door to the penultimate lamella at the top are supported at the left and right by the rigid door guide and at least by an adjacent lamella from above. The topmost lamella, however, is only supported in the left and right door guides and by the lamella below, leaving the top edge unsupported from above.
Under most conditions, the topmost lamella is supported on the left and right edges by the rigid door guide and below by the adjacent lamella. Normally the top edge of the topmost lamella rests against the lintel, the architectural member defining the top of the doorway. If the topmost lamella is subjected to a perpendicular load, as from the wind, no structure is available to prevent it from deflection, particularly at the top edge. In many instances the deflection provides a site for air infiltration from one side of the door to the other, with the concomitant dirt, dust, and other contaminants.
The top edge of the topmost lamella cannot be permanently sealed against the lintel, as this would prevent the door from rolling up to open the doorway. A method or system for providing adequate support for the topmost lamella when the door is closed, while allowing the door comprised of lamella to roll up, is needed.